Thursdays are usually maintenance day for the electrical power supply company in my area. So there was nearly a full day power cut. Luckily, I have a UPS so that sorts out the problem for 8-9 hours. The lead acid battery I use for my UPS is about 3-4 years old, and these being unsealed batteries they last long, really long if maintained properly.
In the past I have had one such battery last for a decade before requiring a replacement.
Unsealed lead acid batteries require two important maintenance activities:
- Topping up distilled water every 6 months
- Applying petroleum jelly / grease on the terminals to prevent corrosion